'emetic' originates from Greek, specifically the word 'emētikos', where the root 'eme-' meant 'to vomit'.

'emetic' changed from Late Latin 'emeticus' (from Greek 'emētikos') and entered English via medical Latin (and influence from French/Latin usage) to become the modern English 'emetic'.

Initially, it meant 'relating to vomiting' and referred especially to substances that induce vomiting; this basic meaning has largely remained the same in modern usage.